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  1. 12V Battery SOC Monitor

    Batteries and Charging
    I have designed and built a flexible and efficient battery charge monitor, in this case for a 12V lead-acid battery, but the same basic design can be used for multiple batteries or lithium cells. The basic circuit consists of a Microchip PIC16F1825, which reads the battery voltage using a...
  2. Cheap 19kW discharge resistor

    Batteries and Charging
    I've been testing battery power and energy for years now and there iwas one idea that i had in my mind to test multi kilowatt of power... Today i decided to go ahead with that idea !!! TIME FOR KILOWATT POWER TEST !!! What's nice with that cheap idea is that it also include the built-in...
  3. Peukert effect during charge as well as discharge

    Batteries and Charging
    Generally the Peukert effect is considered during discharge of lead-acid batteries, but for charging there is a similar effect. I found a detailed explanation of this phenomenon here: and in more detail...
  4. Testing a cheap Li-Ion 18650 cell

    Batteries and Charging
    I just finished a discharge test on one of the Li-Ion cells I bought on eBay at the price of $14/4 pieces including shipping. It is rated for 3600 mAh but my test as received showed only 530 mAh. Here's what I did: Now I need to charge it (while using the datalogger), and then another...
  5. thundersky mac discharge and quality.

    Batteries and Charging
    I'm sure this question would have been asked before but i can't for the life of me find the thread. i was looking into thundersky batteries mainly because there one of the cheapest lithium going around, and the seem to be good quality. with a long life 3000 cycles (10ish years) with a high max...
  6. Discharging a lithium?

    Batteries and Charging
    Just installed lithiums! Went 65 miles on first trip before the Mini BMS beeped at me, then it let me go another 5 miles without beeping. Charged the pack, but I have one battery I bought off of E-bay that shows fully charged before the other batteries I bought from So...
  7. Insight - Will not discharge

    Batteries and Charging
    I got to take my 2000 Honda Insight to the dealers finally now that I have an 'electrical' problem. But wanted to see if anyone have had this problem. My 144 volt battery will charge but will not discharge, most-likely the controller. Just wanted to hear from a fellow Insight owner.
  8. Battery voltage and discharging

    Batteries and Charging
    Hi, I am trying to judge state of charge for a my lifepo(TS90Ah,38 cells, ~120vpack) batteries and looking at the graphs from thundersky I am having issues.... I basically want to know the top voltage (100% charged) and the bottom voltage (70% discharge) range for the 90Ah units. The...